The present invention relates to lubricant devices and methods and more particularly pertains to an apparatus and method for significantly extending machine tool service life. The apparatus and method of the present invention are adaptable to various machining operations including, but not limited to drilling, cutting, reaming, tapping, boring, routing and milling.
Heat generated during the above mentioned machining operations is both detrimental to the workpiece as well as to the machine tool. Excessive heat can cause metallurgical changes within the workpiece while accelerating the wear and dulling of the tool. A dull tool is less effective, generates even more heat during use, and thereby accelerates its own deterioration and ultimate failure. Backing off on the machining rate decreases the amount of heat generated, but results in a slower and less efficient production throughput.
The undesirability of excessive heat build-up associated with machining operations has long been recognized and efforts to reduce temperature generally fall into two categories. The workpiece and machine tool are either cooled or their interface is lubricated. Supplying a cooling fluid either at ambient or subambient temperatures serves to reduce temperatures by transporting away heat generated during the machining operation. Alternatively, lubricating the machining surface reduces the amount of heat actually generated without compromising the effect of the tool on the workpiece. Flooding the workpiece and machine tool with copious amounts of lubricant would suggest that both effects are achieved simultaneously. The lubricant serves to reduce friction and hence heat generation at the outset as well as reduce the resulting temperature by transporting away heat that is generated. A particularly effective variation on this basic theme includes finely dividing or atomizing the lubricant into a mist (see for example, U.S. Pat. Nos. 3,188,010 and 3,939,944) to provide more surface area, and hence achieve a more efficient heat exchange.
Disadvantages associated with prior art devices are generally attributable to the overall effectiveness of a particular method or device. Regardless of the amount of coolant supplied or the amount of lubricant applied, an increased machining rate will ultimately be attained wherein the machine tool and workpiece suffers and throughput efficiency must be forfeited. In addition, the disposal or recycling of toxic or contaminated cooling or lubricating compositions can pose a problem in modern pollution-conscious industrial settings.
A method and apparatus applying such a method is therefore called for that more efficiently reduces the production or build-up of heat during a machining operation and that preferably generates reduced amounts of waste material.